Packaging of liquids



July 7, 1959 E. TEBBUTT 2,893,187

PACKAGING OFLIQUID'S ERIC T'EBBUTTv Inventor By Tal-bsqn scm A torn e yJuly 7, l959 E. TEBBUTT 2,893,187 PACKAGING oF LIQUIDS Filed May 27,1957 2 Sheets-Sheet 2 5R11 TEBBUTT Inventor B53645501: simil@ A Horn e yUnitedStates Patent PACKAGING or LIQUms Eric Tebbutt, Gainsborough,England, assgnor to Rose Brothers (Gainsborough) Limited, Gainsborough,England, aBritish company Application May 27, 1957, Serial No. 661,897

Claims priority, application Great Britain June 2, 1956 3 Claims. (Cl.53--180) This invention relates to the packaging of liquids incontainers formed from heat sealing sheet materials, the material beingfed intermittently in strip form and providing two opposed portionswhich are first sealed longitudinally to form a continuous tube, andthen tranversely at spaced intervals to form a succession of packages,the liquids being introduced into the tube as it is formed. The twoopposed portions of material may be provided by two separate webs, or asingle web may be folded upon itself to provide the two portions.

In packaging liquids in this manner, particularly liquids such asshampoos which readily produce froth when agitated, difficulty has beenfound in preventing the entrainment of air with the liquid withresulting bubbles in the finished packages. Even when the transversesealing takes place below the level of the column of liquid in the tube,this diliculty has been found to persist, when operating at economicalspeeds, presumably because of the turbulence created by the upward surgeof the liquid in the tube as transverse sealing takes place.

In apparatus for producing containers in this manner, it is customary toprovide transverse sealing mechanism that is movable with the tube sothat a period of time is consumed during movement of the sealing meansbetween sealing operations, and an object of the present invention is toutilise that period of time in performing a preliminary nippingoperation on the tube.

According to the present invention, packages are formed in the abovemanner (hereinafter referred to as the described method) by maintaininga substantial head of liquid in the tube above the transverse sealingposition, and, prior to each transverse sealing operation, nipping thetube above the sealing position to displace the liquid in the tube,sealing then taking place substantially simultaneously with the releaseof the nipping pressure. In this manner the main upward surge of theliquid (normally taking place as the transverse sealing elements engagethe tube) takes place before sealing, e.g., at the end of the movementof the tube to form a preceding package. The nipping may thus take placerelatively slowly over the time taken for the sealing members to returnto the sealing position after the completion of the preceding package.The upward surge is thus caused more gently than is the case when it iscaused by the sealing members themselves, and less turbulence iscreated. With the release of the nipping pressure substantiallysimultaneously with the application of the sealing pressure, it is foundthat there is a much reduced surge caused by the sealing members.

The tube is conveniently formed in a substantially vertically downwarddirection in known manner, the liquid being fed into the tube by a pipeextending downwardly into the sealed portion of the tube a distanceequal to the depth of several packages, say up to eight for liquidsprone to the ready production of froth, the liquid being syphoned from aheader tank through the Pipe- In this manner, the head of liquid in thetube is main- ICC tained substantially constant. Preferably, the pipeextends into the tube to a position approaching the transverse sealingposition.

Sheet materials of a thermo-plastic resin composition such as vinylresin and in particular polyvinyl chloride, are particularly suitablefor this method of packaging, the sealing operations being performed byelectrodes to which a high frequency current is applied. When using suchmaterials and sealing the tube in this manner, it is preferable to feedthe tube by means other than the sealing means so as to avoid tensionbeing imparted to the tube by the sealing members during the sealingaction when the portion of the tube being sealed is in a soft condition.Thus, the tube may be fed forward by a pair of pulling members spacedfrom the sealing members, both sets of members being mounted on a commonre ciprocating carriage and being movable synchronously into engagementwith the tube.

A single web of such material may be folded at upon itself and sealedalong one edge to form the tube, a further sealing operation beingsimultaneously performed, if desired, along the opposite edge to providea symmetrical appearance.

The invention is illustrated schematically by the ac-A companyiugdiagrammatic drawings, in which Figure 1 shows in elevation part of amachine for packaging liquid shampoo in sachets of polyvinyl chloride,

Figure 2 shows a detail of Figure l to a larger scale and Figure 3 showsa plan of the detail of Figure 2.

A web 11 of polyvinyl chloride is passed over a guide 12 and folded uponitself to form a tube 13 the folded tube being fed downwardly by a pairof opposed pulling members 14 mounted on carriers 16 each connected bytoggle linkage 17 to a frame 18 secured to a nonrotatable shaft 19mounted in a bed 21 for reciprocation in a vertical direction. Eachlinkage 17 is pivotally attached to an arm 22 pivotally mounted on theframe 1S and having an extension 23 carrying a roller 24 arranged inengagement with a cam 26 secured to a rotatable shaft 27 that is mountedin the bed 21 for vertical reciprocation in synchronism with the shafts19.

The carriers 16 `carry opposed longitudinal sealers 28 for sealing themarginal edges of the tube 13, and also transverse sealers 29 foredecting the transverse seals, the sealers 28 and 29 constitutingelectrodes to which a high frequency current is applied.

The liquid is fed into the tube 13 by a pipe 31 passing into theunsealed portion of the tube and extending downwardly into the sealedportion of the tube a distance equal to the depth of several packages,the liquid being syphoned from a header tank (not shown), through thepipe 31. The packages 32 are completed by the Sealers Z9 and severed bya cutting device 33 to fall onto a delivery conveyor 34.

Arranged above the level of the Sealers 29 is a pair of nipping members36 pivotally mounted on shafts 37 and connected by racks 38, the members36 being oscillated by a cam-operated arm 39 extending from one of themembers 36.

The frames 18 and linkages 17 are operated to cause the carriers 16firstly to move laterally to cause the pullers 14 to engage the tube 13and then downwardly to feed a length of tube equal to the length of apackage 32, the Sealers 28 being moved into engagement with the tube atthe same time to seal a length of the tube somewhat greater than thelength of a package and the sealers 29 to effect the transverse seal.Similarly, the cutting device 33 operates simultaneously to sever acomplete package.

As the carriers 16 move upwardly and outwardly to return the pullingmembers 14 and sealing members 28 and 29 to .the starting position, thenipping members are caused to move relatively slowly (i.e., during thefull period of the return movement of the carriers 16) into engagementwith a filled portion of the tube l to displace the liquid in the tubein readiness forthe next sealing `operation, the nipping pressure beingreleased substanof 'materiaL a pair of reciprocating carriers providedwith f pulling memfbers, longitudinal `sealing members and transversesealing members, said carriers' being movable transvers'ely to cause thepulling and sealing members to move into operative engagement with thetube to elect the forwarding of the tube and its longitudinal andtransverse sealing, and a parof nipping members adapted to engage a lledportion of the tube prior to each transverse seal- Y. 4 ingoperationtodisplace the liquid' in the tube,'the transverse sealing ofthe tube being elected substantially simultaneously with the release ofthe nipping pressure.

2. Apparatus as in claim l, wherein the carriers are attached to areciprocating framework by toggle linkages, and means are provided foroperating the linkages -to produce the transverse movement bf thecarriers.

3, Apparatus asY in claim 2, wherein the operating means arereciproc'ated in synchronism with the frame- 10 Work.

References Cited in the le'ofi this patent UNITED STATES` PATENTS 15V2,616,232 Meyer Nov. 4, l952 2,764,862 Rado Oct. 2, 1956 FOREIGNPATENTS 744,748 YGreatBritain` Mar. 10, 1952

